Sweeping and/or vacuuming may be performed by ordinary cleaners (vacuum cleaners, carpet sweepers) or mobile robots that sweep and/or vacuum. These cleaners and robots may include brush or beater rollers that pick up or help pick up debris. However, while such cleaners or mobile robots may include brush or beater rollers to agitate or sweep debris and dirt away from the floor (or other flat surface), filaments (i.e., hair, thread, string, carpet fiber) may become tightly wrapped around the roller. In particular, pet hair tends to accumulate rapidly and resist removal.